Compound of the imidazole benzanthraquinone series



Fatented Mar. 1, 1%32 neural) s'ra'r as PATENT mmnunorr rrnrnnnncaron, or LEVERKUsEN-QN rHE-RHINE;' GERMANY; nssrenon 'ro- GENERAL ANILINE WORKS, me, on NEW YORK, N. Y., A CORPORATION or unmi- WARE No Drawing. Original application filed. July 30,

23, 1926. Divided and this application The present invention relates to new compounds of the benzanthraquinone series, more particularly to compounds of the general formula:

wherein the nuclei may be substituted by monovalent substituents.

l have found that by suitably heating the imidazoles, obtainable by heating a 1.8-

naphthalicanhydride-4:-benzoyl-o-carboxylic acid with an aromatic ortho-diamine with strong sulfuric acid, they can be transformed cal advantage that comparatively complicated compounds of the'benzanthraquinone series can be prepared by practically very simple and cheap methods.

compounds which described simple I The benzanthraquinone can be prepared in the above manner are valuable orange or darker colored vat dyestulfs of good fastness properties.

The following example will illustrate my invention without restricting it thereto, the

parts being by weight.

Example 41.8 parts of 1.8-naphthoyl-benzimidazol- 4-benzoyl-ortho-carboxylic acid, obtainable from 1.8-naphthalic acid anhydridel-benzoyl-ortho-carboxylic acid and ortho-phenylcoMPoUNnoF THE IMIDAZOLE mmmmammmaa snmns 1928, Serial No. 296,412, and in Germany October filed June 13, 1930. Serial No;-46-1,039.

ene-diamine, are dissolved" in 200 parts of concentrated sulfuric acidand heated for a short time from about 17 0 C. to 180 C. On pouring into a large amountbf water there separates from the sulfuric acid solution the beautiful orange colored imidazole of the corresponding benz'anthraquinone, which is a valuable orange vatd yestuff. The imidazole probably corresponds-to the formula:

In a quite analogous manner other products of interaction from the substitution products of 1.8-naphthalic anhydridel-benzoyl-ortho-carboxylic acid with aromatic ortho-diamines can be transformed into the corresponding benzanthraquinone derivatives in strong sulfuric acid solution at elevated temperature.

It may be mentioned that the above formulae given for my products are not quite definite. The products may also be isomerics of the. formula:

wherein the difierent nuclei may be substituted by monovalent substituents and so far it has not been possible to clear this question definitely. However, according to my 5 knowledge regarding these compounds I believe the formulae given to be the correct ones.

This is a division of my co-pending application Serial No. 296,412, filed July 30th, 1928. V V v i 7 10 I claim The dyestufi' of the probable formula:

said product being-an orange colored compound dyeing cotton from' an alkaline hydrosulfite Vat strong orange shades.

RUDOLF HEIDENREICH. 3o 

